background transparent in blender internal

[David Toro]

how to change a background transparent in blender internal whit fisheye camera?

[Ron Proctor]

Native transparency only works in Cycles.

There's a workaround for the fisheye camera rig with Blender Internal: Make a copy of your scene, remove all lights, make all self-illuminating materials black, make the global background white, and render the scene. You'll get a black and white result. Use composite nodes to combine the RGBA data and don't forget to invert the black and white data for correct alpha.